As everybody knows, electronic devices, when in operation, generate electromagnetic waves. Some of these waves are vital to the operations of the devices generating them, while others are unnecessary or have negative effects.
In recent years, computers have been widely used. The EMI problem resulting from the wide use of computers is becoming more and more common and serious. The higher the operation speed of the computer, the more serious the EMI problem. Therefore, many countries have established inspection and test standards to test electronic devices so as to control the EMI problems. One of the most famous tests is given by the Federal Communication Commission of the United States of America.